Shell nearly doubled earnings in the last three months thanks to higher oil prices and production as new ventures came on stream. Excluding write-offs made for accounting purposes, its earnings were $4.9bn (£3.1bn) for the three months to September, compared with $2.6bn the previous year.

During the quarter the company began production at its oil sands mine in Jackpine, northern Alberta, part of its programme to add another 100,000 barrels a day from these operations. Jackpine is the fifth start-up of 13 projects that have been approved and are scheduled to come on stream this year and next. Shell hopes they will allow it to achieve its target of increasing its 2009 production by 11% by 2012. The company has spent $190bn in its operations since 2004 – almost double the capital investment over the preceding five years – which it hopes will reverse several years of falling production.

It said that it had also approved two new major projects, including Mars B, a deepwater project in the Gulf of Mexico which will eventually add another 100,000 barrels a day production.

The company plans to sell $7bn- $8bn of assets this year and next as it switches out of older producing fields and invests in new ways of producing gas, such as shale gas and coal seam gas, as well as investing in oil sands and in new regions such as Iraq.

Oil and gas production increased by 5% compared with last year to just over 3m barrels a day; sales of liquefied natural gas rose by 22% while the volume of refined oil products it sold was also up. Production was also higher in Nigeria, due to new projects there coming on stream and improved security.

Shell finance director Simon Henry said that it would be unlikely that the Nigerian government would provide its share of the investment needed to develop these fields, so it made sense to sell them to someone who would. Shell has so far sold three of its 30 onshore licences in Nigeria and there have been reports that bidders are circling a further $4bn of its assets up for sale there.

Henry also outlined the cost from BP's Deepwater Horizon disaster. The moratorium on deepwater drilling in the US was lifted last month, but Henry said that it had cost the company $115m in total so far, $59m of which was accounted for in the third quarter and that more charges would be booked in the next quarter. Shell had to idle five rigs and four platforms during the moratorium.

He did not comment on whether Shell would be pursuing BP and any other companies involved for damages. He said that this year Shell's production was 10,000 barrels a day lower than it would otherwise have been without the moratorium. Next year, production would be at least 40,000 barrels lower, and operations could continue to be affected into 2012.

The moratorium meant Shell had to suspend its drilling programme, which is now behind schedule. Its giant Perdido platform in the Gulf, for example, is still only producing around 10,000 barrels a day, despite having a capacity to produce 10 times that figure. The company also had to delay its controversial Alaska drilling programme; Shell announced this month that after the moratorium was lifted it resubmitted its application to drill off the Alaskan coast in the Beaufort Sea next year, but was holding off from a similar application for the Chuchi Sea. Henry said yesterday that it was likely that the new US offshore regulator, which has replaced the discredited MMS in the wake of the disaster, would initially take longer than the customary 30 days to review applications, which would further add to the delay in proceeding with new projects.

In the US, Exxon Mobil posted its biggest increase in third-quarter profits for six years. Net income was $7.35bn, up from $4.73bn in the same three months a year ago, due to higher oil prices, fatter refining margins and a 21% increase in production.